Motor-impedance member device



Dec 31, 1963 J. HENRY-BAUDOT MOTOR-IMPEDANCE MEMBER DEVICE Filed Aug. 30, 1961 United States Patent O 3,3l3i6,43l MTR-MPEDAIICCE MEMBER DEVICE Jacques Henry-Bandot, Antony, France, assigner to Printed Motors, Inc., New York, NX., a corporation of Delaware Filed Aug. 3i), 196i, Ser. No. 134,942 Claims priority, application France Sept. 8, 1960 7 Claims. (Cl Sill-72) The present invention relates to motor-impedance member devices and, more particularly, to devices of the type comprising a motor with an axial air gap for adjusting a potentiometer supplying potential as a function of the angular position of the motor. Such a device, which may be used in servo-mechanisms, may be provided with two potentiometers, one for the control of the device, the other for the electric output According to a feature of the invention, the potentiometer preferably has a resistive track mounted mechanically outside the magnetic gap of the motor and integral with the rotating armature. The potentiometer pick-off brush is mounted on the stator, and the energization of the track is ensured by rotating contacts on slip rings.

According to another feature of the invention, the armature comprises a winding formed of flat conductors adhering intimately to faces of an annular insulating support and the resistive track of the potentiometer is mounted coaxially on the rotor in direct mechanical connection with this armature.

According to another feature of the invention, the resistive track of the potentiometer is enclosed in a cylindrical frame on the outer surface of which is mounted the annular support of the armature.

According7 to still another feature of the invention, the track is formed by a resistive film adhering intimately to the surface of an insulating annular support. This track preferably is applied at least partly against an annular surface of the armature support, free of conductors, or carrying the magnetically inactive portions of the conductors in the armature winding.

According to still another fea-ture of the invention, this track is formed of a resistive film adhering intimately to an annular surface of the armature winding support, free of portions of conductors of the winding.

In accordance with the invention, a motoreimpedance member device comprises means for supplying a magnetic lield across an axial air gap and means comprising a ilat winding rotatable relative to the magnetic field. The device includes means for supplying current to the winding and means comprising an impedance member mounted integrally with the winding. The device also includes means for supplying a potential across said impedance member and potential pick-oft means for deriving an output potential determined by the relative angular position of the winding and the magnetic-field supply means.

For a better understanding of the present invention, together with other and further objects thereof, reference is made to the following description taken in connection with the accompanying drawings and its scope will be pointed out in the appended claims.

Referring to the drawings:

FIG. 1 is a view in section, partly schematic, of a motor-resistor device constructed in accordance with the invention;

FIG. la is an enlarged fragmentary plan view, partly schematic, of an armature-resistor member constructed in accordance with the invention and utilized in the FIG. 1 embodiment;

FlG. 2 is a View in section, partly schematic, of a motor-resistor device constructed in accordance with the invention and having printed-circuit components;

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FIG. 2a is an enlarged fragmentary view in section, of an armature-resistor member constructed in accordance with the invention and utilized in the FIG. 2 embodment;

FIG. 3 is a View in section, partly schematic, of a device constructed in accordance with the invention including two adjustable voltage dividers;

FlG. 4 is a view in section, partly schematic, of a device, constructed in accordance with the invention utilizing two adjustable voltage dividers;

FIG. 5 is a plan view of an armature and resistor member constructed in accordance with the invention;

FIG. 6 is a plan view of another form of armature and resistor member constructed in accordance with the invention.

ln the embodiments of FIGS. 1 -to 4, the stator part of the device is represented as comprising a pair of annular magnetic members 4 and 5, supported by mounting disks 6 and 7 which support by means of bearings lill the shaft 3 of the motor-potentiometer. In the embodiments of FlGS. 2-4, this shaft carries a hub i3 on which is secured the rotating members comprising a flat winding 1 and at least one potentiometer track. The winding 1 is inserted between the annular magnetic members l and 5. rlhese members can both consist of rings of inductive poles or one of the two can simply consist of a magnetic yoke to close a path for the inductive flux of the other. At least two brushes are cooperative with the winding. For a series-wave winding one pair of brushes suffices; for an overlapping or lap winding, two pairs of brushes should be provided as well as two pairs of poles. The brushes are carried by one of the members of the stator, and in each figure one of the two brushes is indicated at 9. The pick-off brush of the potentiometer is also supported by one of the members of the stator. It is indicated as brush il in the figures for each potentiometer shown. For each potentiometer track 2, moreover, one of the stator members supports a pair of brushes ll transmitting current to the potentiometer track Z through two conductive slip rings mounted on an insulating sleeve 12 and connected with the potentiometer track 2. ln the FlGS. 3 and 4 embodiments, this assembly is repeated for the other potentiometer track Z2.

Referring now more particularly to FlGS. l and la, the potentiometer may be wircJ/vound in a conventional manner and the armature may also be wound in the same way. This annular larmature is wound on the frame of the potentiometer which, in turn, is connected to the hub i3 and attached to the frame in any suitable manner, for example, bearing on a collar of the frame and being forced by a threaded ring. The connections to the ends of the potentiometer .are made by wires attached to conductive rings ma, lZb (FIG la) which are in contact with the brushes ll. The pick-off brush 8 may be a wiper which contacts the wire wound resistive member of the potentiometer. In the FIG. 2 embodiment, the armature is a printed-circuit winding and the track of the potentiometer is formed by a resistive film 2 on the face of a dielectric support, as also represented in EFIG. 2a, This track is applied against the armature along the major portion of a ring which preferably covers a part of the conductors of the winding outside the magnetic gap, as indicated in the front view of the rotor in FIG. 5. In a double-faced printed-circuit winding, shown here `as an overlapping Winding by way of illustration, any half-turn conductor comprises a substantially radial central portion with a certain slant extended on both sides by the opposite faces of an insulating support. The support preferably is of insulating material, except in a damped armature, which contains a conductive ring in which eddy currents can flow. This ring is insulated, of

course, from the windiruY proper. For further details concerning these armatures, see the French Certificates of Addition ot Feb. 21, 1957 and June 14, 1957 and of Jan. 8, 1958 of applicant, which are additions to French Patent No. 1,160,498 for improved Electric Rotating Machines (corresponding to US. application Serial No. 691,434).

The brushes of the armature can then ride on the outer slanted parts of the conductors or `on the central parts, if the latter are themselves slanted or curved. But if the rigidity of the support is considered insuiicient, the brushes can ride, as shown in FIG. 2, on conductors behind the support which forms the mechanical rigid track ot the potentiometer'.

FIG. 3 represents an assembly with two potentiometers whose resistive tracks Z and 22 are on insulating members which lock the armature disk of the motor. rThe brushes 9 are then either on the central part or on the outer part of the conductors of the Winding. lf the support of the Winding is not sufficiently rigid, these brushes can be of the type described in the above-mentioned French Certificate of Addition of lune 14, 1957, gripping the periphery of the winding.

For some applications, it may be more advantageous to provide the winding and the potentiometer track on the same annular support, as repre-sented in FIG. 4 in section and FiG. 6 in plan View. if, for example, the resistive track of the potentiometer is formed by a complex of oxides or nitrides, the support, which preferably is temperature-resistant to 656 C., is lirst treated for the deposit of this track by the `known pyrolytic conversion methods of a mist of halogens of metallic constituents in the presence of oxygen. The annular part of the support reserved for the winding is preserved` by a mask during this operation. This is repeated for the other face if two potentiometer tracks are desired in the device, each track having a different resistance from the other controlled by dosing the constituents. Then, by masking the tracks, the surfaces reserved for the Winding may be metallized and conductors may be formed by any suitable means, for example, photoetching and then establishing throughconnections, for example, by the technique of metallizing holes in the conductors and the support.

It desired, the potentiometer track could surround the winding instead of being along its inner periphery, and if desired, two potentiometer tracks could be arranged on the same ace ot the rotor element, one surrounding the Winding and the other being inside the periphery of the winding. Also, for some applications the resistive member may be replaced by anotherimpedance member, for example, an inductive member.

While there have been described what are at present considered to be the preferred embodiments of this invention, it `.vill be obvious to those skilled in the art that various changes and modilications may be made therein Without departing from the invention, and it is, therefore, aimed to cover all such changes and modifications as fall within the true spirit and scope of the invention.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

l. A motor-impedance member device comprising means tor supplying7 a magnetic lield across an axial air gap; means comprising a `tlat winding rotatable relative to said magnetic iield; means for supplying current to said winding; means comprising an impedance member mounted integrally with said winding; means for supplying a potential across said impedance member; and potential pick-oli means for deriving an output potential determined by the relative angular position oi said Winding and said magnetic-field supply means.

2. A motor-resistor device comprising means for supplying a magnetic field across an axial air gap; means comprising a hat winding rotatable within said magnetic field; means for supplying current to said Winding to rotate said winding; means comprising a resistive member rotatably mounted integrally with said winding; means for supplying a potential across said resistive member; and potential pick-oit means for deriving an output potential determined by the angular position of the motor.

3. A motor-resistor device comprising means (for suppiying a magnetic field across an axial air gap; means comprising an insulating `disk having a flat, printedcircuit winding thereon and rotatable within said magnetic field; means for supplying current to said winding to rotate said winding; means comprising a resistive coating ou a surface rotatably mounted integrally with said Winding; means for supplying a potential across said resistive coating; and potential pick-ofi means for deriving an output potential determined by the angular position of the motor.

4. A motor-resistor device comprising means for supplying a magnetic field across an axial air gap; means comprising a iiat Winding rotatable within said magnetic field; means for supplying current to said Winding to rotate said Winding; means comprising a resistive member rotatably mounted integrally with said Winding; means comprising rotatable conductive rings and brushes mounted with said field-supply means for supplying a potential across said resistive member; and potential pickoi means mounted with said field-supply means for deriving an output potential determined by the angular position of the motor.

5. A motor-resistor device comprising means for Supplying a magnetic field across an axial air gap; means comprising a hat winding rotatable Within said magnetic field; means for supplying current to said Winding to rotate said Winding; means comprising a plurality of resistive members rotatably mounted integrally with said Winding; means for supplying a potential lacross said resistive members; and potential pick-ofi means for deriving output potentials determined by the angular position of the motor.

6. An armature for a motor-impedance member device comprising a ldisk having a substantially vannular surface portion substantially covered by a conductive coating forming a substantially uniformly distributed Winding extending generaily radially of said surface portion, said Winding having inner and outer peripheries; another coating on said disk forming an impedance member extending along a periphery of said Winding; and slip rings on said disk and electrically connected to the last-mentioned coating for translating an electrical potential with respect thereto.

7. An armature for a motor-impedance device coinprising a fiat, substantially annular disk having a hat conductive coating thereon forming a substantially uniformly distributed Winding extending generally radially over the major sui-tace portion or" said disk, said `Winding having inner and outer peripheries; a resistive coating on said disk extending along a periphery ot" said Winding; and slip rings on said disk and electrically connected to said resistive coating for translating an electrical potential with respect thereto.

References Qi'ted in the tile of this patent UNITED STATES PATENTS 

1. A MOTOR-IMPEDANCE MEMBER DEVICE COMPRISING MEANS FOR SUPPLYING A MAGNETIC FIELD ACROSS AN AXIAL AIR GAP; MEANS COMPRISING A FLAT WINDING ROTATABLE RELATIVE TO SAID MAGNETIC FIELD; MEANS FOR SUPPLYING CURRENT TO SAID WINDING; MEANS COMPRISING AN IMPEDANCE MEMBER MOUNTED INTEGRALLY WITH SAID WINDING; MEANS FOR SUPPLYING A POTENTIAL ACROSS SAID IMPEDANCE MEMBER; AND POTENTIAL PICK-OFF MEANS FOR DERIVING AN OUTPUT POTENTIAL DETERMINED BY THE RELATIVE ANGULAR POSITION OF SAID WINDING AND SAID MAGNETIC-FIELD SUPPLY MEANS. 